OTP memory devices, which may also be referred to as programmable read-only memory (PROM), are used in various different applications to provide flexible means for storing program code or other data (e.g. calibration data). By way of example, OTP memory devices may be provided in conjunction with a controller on an integrated circuit (IC). In a particular example, OTP memory may be used on a driver circuit for a solid state lighting device (e.g. an Light Emitting Diode, LED, lamp) to store calibration data, which is determined and programmed at the end of the manufacturing process of such a solid state lighting device.
An OTP memory device typically comprises a plurality of pins which have different functions for the programming phase (when programming the OTP memory device to store data) and/or for the reading phase (when providing the stored data during operation of the IC which comprises the OTP memory device). A particular one of these pins is the supply voltage VPP pin (also referred to as the OTP supply voltage pin, or more generally to the device supply voltage pin). The OTP supply voltage VPP which may be applied to the OTP memory device typically takes on at least two different values: a read level (e.g. 1.5V) which is used during normal operation (i.e. during the reading phase) of the OTP memory device for reading the data which has been stored in the OTP memory device, and a programming level (e.g. 7.5V) which is used during the programming phase for allowing the OTP memory device to be programmed.